WTO Regulatory Compliance & Safety Standards 3 — Questions and Answers
Question 1: A community water system serving 10,000 people must monitor for lead and copper at customer taps. During a monitoring period, how many samples are required under the Lead and Copper Rule?
- 10
- 30
- 50 (Correct answer)
- 100
Correct answer: 50
Under the Lead and Copper Rule, a community water system serving 3,301–10,000 people must collect 30 samples, but systems serving more than 10,000 must collect 50 first-draw samples.
Question 2: What is the Action Level (AL) for copper under the Lead and Copper Rule?
- 0.005 mg/L
- 0.015 mg/L
- 1.3 mg/L (Correct answer)
- 2.0 mg/L
Correct answer: 1.3 mg/L
The Action Level for copper is 1.3 mg/L; if exceeded at the 90th percentile of samples, the system must take corrective action.
Question 3: Which disinfection byproduct rule requires monitoring for haloacetic acids (HAA5) and total trihalomethanes (TTHM)?
- Surface Water Treatment Rule
- Stage 2 Disinfectants and Disinfection Byproducts Rule (Correct answer)
- Revised Total Coliform Rule
- Groundwater Rule
Correct answer: Stage 2 Disinfectants and Disinfection Byproducts Rule
The Stage 2 D/DBP Rule requires monitoring and compliance with TTHM and HAA5 MCLs based on locational running annual averages (LRAA).
Question 4: Process Safety Management (PSM) regulations under OSHA apply to water treatment facilities that store chlorine gas above what threshold quantity?
- 100 pounds
- 500 pounds
- 1,500 pounds (Correct answer)
- 2,500 pounds
Correct answer: 1,500 pounds
OSHA PSM regulations are triggered for chlorine gas when the quantity on-site meets or exceeds the threshold quantity of 1,500 pounds.
Question 5: Under the Emergency Planning and Community Right-to-Know Act (EPCRA), a water utility must report an extremely hazardous substance spill to the LEPC if it exceeds the:
- Action Level
- Reportable Quantity (Correct answer)
- Maximum Contaminant Level
- Permissible Exposure Limit
Correct answer: Reportable Quantity
EPCRA Section 304 requires immediate notification to the Local Emergency Planning Committee (LEPC) if an accidental release exceeds the Reportable Quantity (RQ).
Question 6: Which drinking water regulation specifically addresses microbial and disinfection byproduct risks in systems using surface water or groundwater under the influence of surface water?
- Groundwater Rule
- Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) (Correct answer)
- Total Coliform Rule
- Lead and Copper Rule
Correct answer: Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR)
The LT2ESWTR requires additional Cryptosporidium treatment for surface water systems with higher source water contamination levels.
Question 7: When a water system exceeds an MCL, which type of public notice is required for a non-acute violation?
- Tier 1 — within 24 hours
- Tier 2 — within 30 days (Correct answer)
- Tier 3 — within 1 year
- No notice is required for non-acute violations
Correct answer: Tier 2 — within 30 days
Non-acute MCL violations require a Tier 2 notice, which must be issued within 30 days of the system learning of the violation.
WTO Regulatory Compliance & Safety Standards 3
A community water system serving 10,000 people must monitor for lead and copper at customer taps.
During a monitoring period, how many samples are required under the Lead and Copper Rule?